The difficulties in backing a vehicle to engage a trailer hitch are well known. A miscalculation on the part of the driver can result in damage to the vehicle, typically by the trailer coupling body striking the rear of the vehicle, and may also result in damage to the trailer, its contents, or injury to people or objects nearby.
A challenge specifically arises in aligning the ball, pintle or other hitch (“hitch”) with the trailer coupling body (“coupler”) both laterally and longitudinally. Lateral alignment requires that the coupler is centered side to side with respect to the vehicle. Longitudinal alignment requires that the coupler is the correct distance from the rear of the vehicle.
One device to facilitate alignment is disclosed in U.S. Pat. No. 5,669,621 to Lockwood, wherein one post and flag is disposed proximate the hitch, and another post and flag is disposed proximate the coupler. Using this device, the driver maneuvers the vehicle to bring the flags in proximity. This device, however, requires that the driver properly gauges the lateral and longitudinal alignment between flags, including the rate at which the flags are converging. As a practical matter, this is difficult for many drivers.
U.S. Pat. No. 6,273,448 to Cross, and U.S. Patent Publications 2005/0218626 to Kwilinski, and 2006/0220345 to Schmidt, present alternative means to gauge longitudinal alignment. Specifically, in these references the trailer hitch strikes a panel or a part of the flag post, causing either a visible or audible alarm, or movement of the flag pole, to alert the driver when the hitch is near the coupler. These methods, however, still present a danger of the hitch missing the strike zone of the device, whereby the hitch and coupler pass each other, with attendant consequences as described above. Moreover, in all of these devices, there are no indications until the hitch and coupler are very close, and thus a vehicle backing at speed may simply overshoot the target, as may occur with the device of Lockwood.
U.S. Pat. No. 6,851,697 to Kinnard extends a metal tape in the direction of the vehicle, whereby when the hitch and coupler are a more significant distance apart, an indicator begins to reveal their relative proximity. Kinnard additionally activates if there is lateral misalignment, as there is no longer a necessity of hitting a strike zone near the coupler.
In Kinnard, however, heavy, rigid materials are required, as well as a stout mounting system and bracket body which are bolted to the jack post of a trailer. Trailers without a jack post cannot accommodate the device of Kinnard. Further, there is a requirement that the jackpost be positioned sufficiently close to the forward edge of the trailer, so that the device may contact the vehicle when extended.
Permanently mounted devices, such as disclosed in Kinnard, may not have a need to be buoyant, as they are not likely to fall into the water. However, a device which is quickly and easily removed without tools would greatly benefit from being buoyant, if dropped into water. Kinnard, however, is not adapted to be floatable without the addition of a substantial quantity of buoyant materials.
It would further be advantageous to have a device which offers a soft, dampened contact, as opposed to contact by a rigid metallic tape or the like. In Kinnard, the metal tape is described as usually contacting the license plate, which does not pose as much a problem with respect to scratching or denting as the painted bodywork of a vehicle. As a practical matter, however, contact with the bodywork of the vehicle can be expected, and the device must therefore not pose a potential hazard to the vehicle's finish.
Another advantage would be to have a device which, in addition to other attributes, greatly facilitates visual lateral and longitudinal alignment, is of low cost, that can easily moved from one trailer to another, is quickly and easily calibrated, is sufficiently light and buoyant to float, is easier to see, and presents a minimum of risk of damage to the vehicle or trailer in use.